Interleukin-1 receptor-associated kinase-4 (IRAK4) is a serine-threonine kinase which acts as a mediator in interleukin-1/Toll-like receptor (IL-1/TLR) signaling cascades. More particularly, IRAK4 is involved in activation of adaptor protein myeloid differentiation primary response gene 88 (MyD88) signaling cascades and is hypothesized to play a role in inflammation related disorders as well as in oncology and non-alcoholic steatohepatitis (NASH). Signaling through IL-1R/TLR results in the activation of MyD88 which recruits IRAK4 and IRAK1 to form a signaling complex. This complex then interacts with a series of kinases, adaptor proteins, and ligases, ultimately resulting in the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein-1, inducing the generation of inflammatory cytokines.
Therefore, inhibitors of IRAK4 may be useful in the treatment of inflammatory disorders, including autoimmune disorders, such as rheumatoid arthritis (RA), inflammatory bowel disease (IBD), gout, Lyme arthritis, systemic lupus erythematosus (SLE), Sjogren's syndrome and viral myocarditis. (Joosten, L. A. B et al., TOLL-LIKE RECEPTORS AND CHRONIC INFLAMMATION IN RHEUMATIC DISEASES: NEW DEVELOPMENTS, Nat. Rev. Rheumatol., 346| Jun. 2016 12; 344-357 Published online 12 May 2016) (Valaperti, A. et al., INNATE IMMUNE INTERLEUKIN-1RECEPTOR-ASSOCIATED KINASE 4 EXACERBATES VIRAL MYOCARDITIS BY REDUCING CCR5+CD11b+ MONOCYTE MIGRATION AND IMPAIRING INTERFERON PRODUCTION, Circulation, 128| Sep. 2013 14; 1542-1554), as well as Type I interferonopathies, such as Aicardi-Goutières syndrome, Familial chilblain lupus, and Retinal vasculopathy with cerebral leukodystrophy, (Lee-Kirsch et al., TYPE I INTERFERONOPATHIES—AN EXPANDING DISEASE SPECTRUM OF IMMUNODYSREGULATION, Semin. Immunopathol. (2015) 37:349-357).
In addition, certain cancers, including lymphomas, may contain one or more mutations in the MYD88 adaptor protein, leading to a constitutively active signaling cascade that may promote survival of tumor cells. (Kelly et al., IRAK4 inhibitors for autoimmunity and lymphoma, J. Exp. Med. 2015 Vol. 212 No. 13 2189-2201)
Therefore, an inhibitor of IRAK4 may be useful in the treatment of cancers, including lymphomas.
There are currently no approved IRAK4 inhibiting pharmaceuticals. Therefore, it would be useful to provide an IRAK4 inhibiting compound with properties suitable for administration as a pharmaceutical agent to a mammal, particularly a human.
WO2016210034, WO2016210036, WO2015150995, WO2016127024, and WO2016210037 recite compounds said to be useful as IRAK4 inhibitors.